Table 5 Estimated values of unknown parameters for DS-II.

Total number of faults present in software at time \(\:\varvec{{\prime\:}}\varvec{t}\varvec{{\prime\:}}\) (N)

149

Fault detection rate for \(\:0\le\:\varvec{t}\le\:\varvec{\tau\:}\:\) (b₁)

0.0426

Fault detection rate for \(\:\varvec{\tau\:}<\varvec{t}\le\:\varvec{t}\:\:\) (b₂)

0.001

new fault introduction rate for \(\:0\le\:\varvec{t}\le\:\varvec{\tau\:}\) (\(\:{\varvec{\alpha\:}}_{1})\)

0.0057

new fault introduction rate for\(\:\:\varvec{\tau\:}<\varvec{t}\le\:\varvec{t}\) (\(\:{\varvec{\alpha\:}}_{2})\)

0.001

uncertainty level for \(\:0\le\:\varvec{t}\le\:\varvec{\tau\:}\) (\(\:{\varvec{\sigma\:}}_{1})\)

0.2985

uncertainty level for \(\:\varvec{\tau\:}<\varvec{t}\le\:\varvec{t}\) (\(\:{\varvec{\sigma\:}}_{2})\)

0.463

change point (\(\:\varvec{\tau\:})\)

13